The present invention relates to an electronic engine control apparatus, and more particularly to an electronic engine control apparatus whereby the driving characteristics of a vehicle are adjusted so as to match a driver's intent of how to drive the vehicle. Namely, the driving characteristics are adjusted in accordance with a driving environment of a vehicle and/or a driver's preference to the way he or she drives the vehicle.
Conventional engine control electronic apparatus of commercial vehicles have the engine control characteristics adjusted to match the driving characteristics which are most preferred by vehicle users (drivers and fellow persons) under the driving (running) environments most frequently encountered. A so-called greatest common divisor type matching has been adopted for the engine control characteristics. The term "matching" herein means adjusting an engine control unit so as to meet the requirements of a vehicle driver.
In a known engine control apparatus for electronically controlling a throttle valve, a method of electronically controlling the sensitivity of opening a throttle valve relative to an amount of accelerator pedal depression in accordance with the accelerator pedal depression amount and speed in adopted. This method is disclosed in U.S. Pat. No. 4,597,049.
For the conventional electronic engine control, however, a method has been adopted whereby the control is conducted based on the engine conditions during several engine strokes. In other words, the main function of such engine control is to control the engine in accordance with the measured results obtained for a short period. Thus, the engine control apparatus is not equipped with a unit for discriminating driving environments and drivers preferences in accordance with the measured results obtained for a long period of several tens to hundreds engine strokes. Such a long measuring period for discrimination is herein defined as an evaluation period.
The above-mentioned greatest common divisor type matching does not meet all driving environments and various driver's preferences (feelings). Also, the above-mentioned method whereby a change in the sensitivity of opening a throttle valve relative to an amount of acceleration pedal depression, as is the case of the above-described U.S. Patent, poses a problem when a sensitivity change occurs because of racing or double clutching.